A video conference system for performing a video conference (may be referred to as “the TV conference”) with a remote location in order to meet requests for reducing expenses and times for a business trip is popularized. In the video conference system, conversations (communications) are performed by transmitting/receiving image data and sound data (audio data) directly between a plurality of video conference terminals.
Recently, a video conference system which performs transmitting/receiving the image data and the sound data between a plurality of video conference terminals via a relay apparatus which relays the image data and the sound data has been spread in the art. The above described video conference system, in which the relay apparatus relays the image data and the sound data, uses an image coding technique for minimizing failure of communication even if temporary failure of a network occurs or a processing capability of the video conference terminal is low. Further, the image coding technique uses a standard called as H.264/SVC (Scalable Video Coding) (refer to Patent document 1).
However, under a circumstance in which transmission capacity is lowered due to congestion of the communication network or the like, a reception of the image data may be delayed at a reception side video conference terminal. Patent document 1 discloses a technique which stops transmitting/receiving the image data and performs transmitting/receiving only the sound data in order to continue communicating. Thereby, an image with strangeness which shows an object of a communication partner side (an opposite side) due to a long delay is not displayed at the reception side (in this case, own side) video conference terminal of the image data.
However, when a user at the communication partner side stops talking in a state in which the image which shows the object of the communication partner side is not displayed at the own side, not only the image but also the sound is not output at the own side. Thus, the user (oneself) at the own side cannot recognize a reason why the image of the communication partner side (the figure of the communication partner or the like) is not displayed. That is, the user cannot recognize whether the user at the communication partner side stops communicating or the image data is not transmitted because the bandwidth of the communication is narrow.